You are told you have knee arthritis. The advice the doctor gives you is to go home, rest your knee, take anti-inflammatory drugs, lose some weight, wait until you are older and then get an artificial knee replacement. This advice is awful. Here's why.

“Push through the pain.” “No pain, no gain,” we were told in our youth. These are outside voices – but listening to your body and knowing when to stop is the key to diminishing self-inflicted injuries and lengthening your sports career.

Running is safe. No joint is injured solely by running, despite what you may have heard. Running only damages already damaged joints. You can run forever if you have healthy joints and good running mechanics.